APA Style
Gruber, Gary R. , PHD. ().
The World's 200 Hardest Brain Teasers .
:
Sourcebooks, Inc..
Chicago Style
Gruber, Gary R. , PHD.
The World's 200 Hardest Brain Teasers.
:
Sourcebooks, Inc.,
.
Text.
MLA Style
Gruber, Gary R. , PHD.
The World's 200 Hardest Brain Teasers.
:
Sourcebooks, Inc.,
.
Text.
Turabian Style
Gruber, Gary R. , PHD.
The World's 200 Hardest Brain Teasers.
:
Sourcebooks, Inc.,
.
Print.